OIII 12nm CCD Filter - 50mm Square Unmounted
Astronomik
From $319.95
3 stores
The Astronomik OIII 12nm CCD Filter is a narrowband emission-line filter optimized for CCD astrophotography, isolating the doubly ionized oxygen emission lines at 496nm and 501nm to reveal fine structure in planetary and emission nebulae while suppressing light pollution and skyglow. With a 12nm full-width-half-maximum (FWHM) bandwidth, this filter balances sensitivity with excellent guide star availability for cameras with integrated autoguiders, making it ideal for imaging from light-polluted suburban observing sites. The 50mm square unmounted format fits standard filter wheels and delivers typical transmission rates around 95%, with diffraction-limited performance and an integrated infrared blocker up to 1150nm.
Specifications
| Central Wavelength | 496 |
| Minimum Transmission | 90% |
| Coating Type | MFR |
| Filter Size | 50 in |
| Glass Thickness | 1 mm |
| Diffraction Limited | ✓ |
| Format | Square Unmounted |
| Recommended Aperture Ratio Range | f/3 to f/15 |
| Parfocal | ✓ |
| Filter Type | Narrowband Emission-Line (OIII) |
| Warranty | 10 |
| Bandwidth (FWHM) | 12 |
| IR Blocker | up to 1150 nm |
| Typical Transmission | 95% |